小编Die*_*dal的帖子

我有一个包含以下表格的数据库:

CREATE TABLE IF NOT EXISTS `app_user` (
  `user_id` INT NOT NULL,
  `user_name` VARCHAR(45) NOT NULL,
  PRIMARY KEY (`user_id`))
ENGINE = InnoDB;

CREATE TABLE IF NOT EXISTS `user_folder` (
  `user_id` INT NOT NULL,
  `document_id` INT NOT NULL,
  PRIMARY KEY (`user_id`, `document_id`),
  CONSTRAINT `fk_user_document_user`
    FOREIGN KEY (`user_id`)
    REFERENCES `zinc`.`app_user` (`user_id`)
    ON DELETE CASCADE
    ON UPDATE CASCADE)
ENGINE = InnoDB;

CREATE TABLE IF NOT EXISTS `folder_content` (
  `user_id` INT NOT NULL,
  `document_id` INT NOT NULL,
  `content_id` INT NOT NULL,
  PRIMARY KEY (`user_id`, …